ci: Fix wait-on-check-action usage (#730)

Co-authored-by: Martin Adámek <[email protected]>

.github/workflows/release.yaml

@@ -43,11 +43,26 @@ jobs:
                   custom_version: ${{ inputs.custom_version }}
                   existing_changelog_path: CHANGELOG.md
 
+    # If github.ref points to a [skip ci] commit, we assume that it was added by the pre_release workflow, 
+    # which doesn't push the commit if code checks don't pass.
+    # Otherwise, the checks will have been triggered by the `run_code_checks` workflow.
     wait_for_checks:
         name: Wait for code checks to pass
         runs-on: ubuntu-latest
         steps:
+            - name: Checkout repository
+              uses: actions/checkout@v4
+            - name: Check if the head commit contains [skip ci]
+              id: check_skip
+              run: |
+                  if git log --format=%B -n 1 ${{ github.sha }} | head -n 1 | grep '\[skip ci\]$'; then
+                    echo 'skipped=true' >> $GITHUB_OUTPUT
+                  else
+                    echo 'skipped=false' >> $GITHUB_OUTPUT
+                  fi
+
             - uses: lewagon/[email protected]
+              if: ${{ steps.check_skip.outputs.skipped == 'false' }}
               with:
                   ref: ${{ github.ref }}
                   repo-token: ${{ secrets.GITHUB_TOKEN }}